The test client is a Python class that acts as a dummy Web browser, allowing
you to test your views and interact with your Django-powered application
programmatically.

Some of the things you can do with the test client are:

Simulate GET and POST requests on a URL and observe the response –
everything from low-level HTTP (result headers and status codes) to
page content.

See the chain of redirects (if any) and check the URL and status code at
each step.

Test that a given request is rendered by a given Django template, with
a template context that contains certain values.

Note that the test client is not intended to be a replacement for Selenium or
other “in-browser” frameworks. Django’s test client has a different focus. In
short:

Use Django’s test client to establish that the correct template is being
rendered and that the template is passed the correct context data.

Use in-browser frameworks like Selenium to test rendered HTML and the
behavior of Web pages, namely JavaScript functionality. Django also
provides special support for those frameworks; see the section on
LiveServerTestCase for more details.

A comprehensive test suite should use a combination of both test types.

As this example suggests, you can instantiate Client from within a session
of the Python interactive interpreter.

Note a few important things about how the test client works:

The test client does not require the Web server to be running. In fact,
it will run just fine with no Web server running at all! That’s because
it avoids the overhead of HTTP and deals directly with the Django
framework. This helps make the unit tests run quickly.

When retrieving pages, remember to specify the path of the URL, not the
whole domain. For example, this is correct:

>>> c.get('/login/')

This is incorrect:

>>> c.get('http://www.example.com/login/')

The test client is not capable of retrieving Web pages that are not
powered by your Django project. If you need to retrieve other Web pages,
use a Python standard library module such as urllib.

Although the above example would work in the Python interactive
interpreter, some of the test client’s functionality, notably the
template-related functionality, is only available while tests are
running.

The reason for this is that Django’s test runner performs a bit of black
magic in order to determine which template was loaded by a given view.
This black magic (essentially a patching of Django’s template system in
memory) only happens during test running.

By default, the test client will disable any CSRF checks
performed by your site.

If, for some reason, you want the test client to perform CSRF
checks, you can create an instance of the test client that
enforces CSRF checks. To do this, pass in the
enforce_csrf_checks argument when you construct your
client:

Makes a POST request on the provided path and returns a
Response object, which is documented below.

The key-value pairs in the data dictionary are used to submit POST
data. For example:

>>> c=Client()>>> c.post('/login/',{'name':'fred','passwd':'secret'})

...will result in the evaluation of a POST request to this URL:

/login/

...with this POST data:

name=fred&passwd=secret

If you provide content_type (e.g. text/xml for an XML
payload), the contents of data will be sent as-is in the POST
request, using content_type in the HTTP Content-Type header.

If you don’t provide a value for content_type, the values in
data will be transmitted with a content type of
multipart/form-data. In this case, the key-value pairs in
data will be encoded as a multipart message and used to create the
POST data payload.

To submit multiple values for a given key – for example, to specify
the selections for a <selectmultiple> – provide the values as a
list or tuple for the required key. For example, this value of data
would submit three selected values for the field named choices:

{'choices':('a','b','d')}

Submitting files is a special case. To POST a file, you need only
provide the file field name as a key, and a file handle to the file you
wish to upload as a value. For example:

(The name attachment here is not relevant; use whatever name your
file-processing code expects.)

Note that if you wish to use the same file handle for multiple
post() calls then you will need to manually reset the file
pointer between posts. The easiest way to do this is to
manually close the file after it has been provided to
post(), as demonstrated above.

You should also ensure that the file is opened in a way that
allows the data to be read. If your file contains binary data
such as an image, this means you will need to open the file in
rb (read binary) mode.

Makes a HEAD request on the provided path and returns a
Response object. This method works just like Client.get(),
including the follow, secure and extra arguments, except
it does not return a message body.

If your site uses Django’s authentication system
and you deal with logging in users, you can use the test client’s
login() method to simulate the effect of a user logging into the
site.

After you call this method, the test client will have all the cookies
and session data required to pass any login-based tests that may form
part of a view.

The format of the credentials argument depends on which
authentication backend you’re using
(which is configured by your AUTHENTICATION_BACKENDS
setting). If you’re using the standard authentication backend provided
by Django (ModelBackend), credentials should be the user’s
username and password, provided as keyword arguments:

>>> c=Client()>>> c.login(username='fred',password='secret')# Now you can access a view that's only available to logged-in users.

If you’re using a different authentication backend, this method may
require different credentials. It requires whichever credentials are
required by your backend’s authenticate() method.

login() returns True if it the credentials were accepted and
login was successful.

Finally, you’ll need to remember to create user accounts before you can
use this method. As we explained above, the test runner is executed
using a test database, which contains no users by default. As a result,
user accounts that are valid on your production site will not work
under test conditions. You’ll need to create users as part of the test
suite – either manually (using the Django model API) or with a test
fixture. Remember that if you want your test user to have a password,
you can’t set the user’s password by setting the password attribute
directly – you must use the
set_password() function to
store a correctly hashed password. Alternatively, you can use the
create_user() helper
method to create a new user with a correctly hashed password.

The get() and post() methods both return a Response object. This
Response object is not the same as the HttpResponse object returned
by Django views; the test response object has some additional data useful for
test code to verify.

A list of Template instances used to render the final content, in
the order they were rendered. For each template in the list, use
template.name to get the template’s file name, if the template was
loaded from a file. (The name is a string such as
'admin/index.html'.)

You can also use dictionary syntax on the response object to query the value
of any settings in the HTTP headers. For example, you could determine the
content type of a response using response['Content-Type'].

If you point the test client at a view that raises an exception, that exception
will be visible in the test case. You can then use a standard try...except
block or assertRaises() to test for exceptions.

The only exceptions that are not visible to the test client are
Http404,
PermissionDenied, SystemExit, and
SuspiciousOperation. Django catches these
exceptions internally and converts them into the appropriate HTTP response
codes. In these cases, you can check response.status_code in your test.

importunittestfromdjango.testimportClientclassSimpleTest(unittest.TestCase):defsetUp(self):# Every test needs a client.self.client=Client()deftest_details(self):# Issue a GET request.response=self.client.get('/customer/details/')# Check that the response is 200 OK.self.assertEqual(response.status_code,200)# Check that the rendered context contains 5 customers.self.assertEqual(len(response.context['customers']),5)

Django’s TestCase class (described below) makes use of database transaction
facilities to speed up the process of resetting the database to a known state
at the beginning of each test. A consequence of this, however, is that the
effects of transaction commit and rollback cannot be tested by a Django
TestCase class. If your test requires testing of such transactional
behavior, you should use a Django TransactionTestCase.

TransactionTestCase and TestCase are identical except for the manner
in which the database is reset to a known state and the ability for test code
to test the effects of commit and rollback:

A TransactionTestCase resets the database after the test runs by
truncating all tables. A TransactionTestCase may call commit and rollback
and observe the effects of these calls on the database.

A TestCase, on the other hand, does not truncate tables after a test.
Instead, it encloses the test code in a database transaction that is rolled
back at the end of the test. Both explicit commits like
transaction.commit() and implicit ones that may be caused by
transaction.atomic() are replaced with a nop operation. This
guarantees that the rollback at the end of the test restores the database to
its initial state.

Warning

TestCase running on a database that does not support rollback (e.g. MySQL with the
MyISAM storage engine), and all instances of TransactionTestCase, will
roll back at the end of the test by deleting all data from the test database
and reloading initial data for apps without migrations.

Apps with migrations will not see their data reloaded;
if you need this functionality (for example, third-party apps should enable
this) you can set serialized_rollback=True inside the
TestCase body.

Warning

While commit and rollback operations still appear to work when
used in TestCase, no actual commit or rollback will be performed by the
database. This can cause your tests to pass or fail unexpectedly. Always
use TransactionTestCase when testing transactional behavior or any code
that can’t normally be executed in autocommit mode
(select_for_update() is an
example).

This class provides some additional capabilities that can be useful for testing
Web sites.

Converting a normal unittest.TestCase to a Django TestCase is
easy: Just change the base class of your test from 'unittest.TestCase' to
'django.test.TestCase'. All of the standard Python unit test functionality
will continue to be available, but it will be augmented with some useful
additions, including:

Automatic loading of fixtures.

Wraps each test in a transaction.

Creates a TestClient instance.

Django-specific assertions for testing for things like redirection and form
errors.

LiveServerTestCase does basically the same as
TransactionTestCase with one extra feature: it launches a
live Django server in the background on setup, and shuts it down on teardown.
This allows the use of automated test clients other than the
Django dummy client such as, for example, the Selenium
client, to execute a series of functional tests inside a browser and simulate a
real user’s actions.

By default the live server’s address is 'localhost:8081' and the full URL
can be accessed during the tests with self.live_server_url. If you’d like
to change the default address (in the case, for example, where the 8081 port is
already taken) then you may pass a different one to the test command
via the --liveserver option, for example:

$ ./manage.py test --liveserver=localhost:8082

Another way of changing the default server address is by setting the
DJANGO_LIVE_TEST_SERVER_ADDRESS environment variable somewhere in your
code (for example, in a custom test runner):

In the case where the tests are run by multiple processes in parallel (for
example, in the context of several simultaneous continuous integration
builds), the processes will compete for the same address, and therefore your
tests might randomly fail with an “Address already in use” error. To avoid this
problem, you can pass a comma-separated list of ports or ranges of ports (at
least as many as the number of potential parallel processes). For example:

This example will automatically open Firefox then go to the login page, enter
the credentials and press the “Log in” button. Selenium offers other drivers in
case you do not have Firefox installed or wish to use another browser. The
example above is just a tiny fraction of what the Selenium client can do; check
out the full reference for more details.

LiveServerTestCase now simply publishes the contents of the file system
under STATIC_ROOT at the STATIC_URL.

Note

When using an in-memory SQLite database to run the tests, the same database
connection will be shared by two threads in parallel: the thread in which
the live server is run and the thread in which the test case is run. It’s
important to prevent simultaneous database queries via this shared
connection by the two threads, as that may sometimes randomly cause the
tests to fail. So you need to ensure that the two threads don’t access the
database at the same time. In particular, this means that in some cases
(for example, just after clicking a link or submitting a form), you might
need to check that a response is received by Selenium and that the next
page is loaded before proceeding with further test execution.
Do this, for example, by making Selenium wait until the <body> HTML tag
is found in the response (requires Selenium > 2.13):

deftest_login(self):fromselenium.webdriver.support.waitimportWebDriverWaittimeout=2...self.selenium.find_element_by_xpath('//input[@value="Log in"]').click()# Wait until the response is receivedWebDriverWait(self.selenium,timeout).until(lambdadriver:driver.find_element_by_tag_name('body'))

The tricky thing here is that there’s really no such thing as a “page load,”
especially in modern Web apps that generate HTML dynamically after the
server generates the initial document. So, simply checking for the presence
of <body> in the response might not necessarily be appropriate for all
use cases. Please refer to the Selenium FAQ and
Selenium documentation for more information.

Every test case in a django.test.*TestCase instance has access to an
instance of a Django test client. This client can be accessed as
self.client. This client is recreated for each test, so you don’t have to
worry about state (such as cookies) carrying over from one test to another.

A test case for a database-backed Web site isn’t much use if there isn’t any
data in the database. To make it easy to put test data into the database,
Django’s custom TransactionTestCase class provides a way of loading
fixtures.

A fixture is a collection of data that Django knows how to import into a
database. For example, if your site has user accounts, you might set up a
fixture of fake user accounts in order to populate your database during tests.

The most straightforward way of creating a fixture is to use the
manage.pydumpdata command. This assumes you
already have some data in your database. See the dumpdatadocumentation for more details.

Note

If you’ve ever run manage.pymigrate, you’ve
already used a fixture without even knowing it! When you call
migrate in the database for the first time, Django
installs a fixture called initial_data. This gives you a way
of populating a new database with any initial data, such as a
default set of categories.

Fixtures with other names can always be installed manually using
the manage.pyloaddata command.

Initial SQL data and testing

Django provides a second way to insert initial data into models –
the custom SQL hook. However, this technique
cannot be used to provide initial data for testing purposes.
Django’s test framework flushes the contents of the test database
after each test; as a result, any data added using the custom SQL
hook will be lost.

Once you’ve created a fixture and placed it in a fixtures directory in one
of your INSTALLED_APPS, you can use it in your unit tests by
specifying a fixtures class attribute on your django.test.TestCase
subclass:

fromdjango.testimportTestCasefrommyapp.modelsimportAnimalclassAnimalTestCase(TestCase):fixtures=['mammals.json','birds']defsetUp(self):# Test definitions as before.call_setup_methods()deftestFluffyAnimals(self):# A test that uses the fixtures.call_some_test_code()

Here’s specifically what will happen:

At the start of each test case, before setUp() is run, Django will
flush the database, returning the database to the state it was in
directly after migrate was called.

Then, all the named fixtures are installed. In this example, Django will
install any JSON fixture named mammals, followed by any fixture named
birds. See the loaddata documentation for more
details on defining and installing fixtures.

This flush/load procedure is repeated for each test in the test case, so you
can be certain that the outcome of a test will not be affected by another test,
or by the order of test execution.

By default, fixtures are only loaded into the default database. If you are
using multiple databases and set multi_db=True, fixtures will be loaded into all databases.

If your application provides views, you may want to include tests that use the
test client to exercise those views. However, an end user is free to deploy the
views in your application at any URL of their choosing. This means that your
tests can’t rely upon the fact that your views will be available at a
particular URL.

In order to provide a reliable URL space for your test,
django.test.*TestCase classes provide the ability to customize the URLconf
configuration for the duration of the execution of a test suite. If your
*TestCase instance defines an urls attribute, the *TestCase will use
the value of that attribute as the ROOT_URLCONF for the duration
of that test.

Django sets up a test database corresponding to every database that is
defined in the DATABASES definition in your settings
file. However, a big part of the time taken to run a Django TestCase
is consumed by the call to flush that ensures that you have a
clean database at the start of each test run. If you have multiple
databases, multiple flushes are required (one for each database),
which can be a time consuming activity – especially if your tests
don’t need to test multi-database activity.

As an optimization, Django only flushes the default database at
the start of each test run. If your setup contains multiple databases,
and you have a test that requires every database to be clean, you can
use the multi_db attribute on the test suite to request a full
flush.

This test case will flush all the test databases before running
test_index_page_view.

The multi_db flag also affects into which databases the
attr:TransactionTestCase.fixtures are loaded. By default (when
multi_db=False), fixtures are only loaded into the default database.
If multi_db=True, fixtures are loaded into all databases.

For testing purposes it’s often useful to change a setting temporarily and
revert to the original value after running the testing code. For this use case
Django provides a standard Python context manager (see PEP 343) called
settings(), which can be used like this:

fromdjango.testimportTestCaseclassLoginTestCase(TestCase):deftest_login(self):# First check for the default behaviorresponse=self.client.get('/sekrit/')self.assertRedirects(response,'/accounts/login/?next=/sekrit/')# Then override the LOGIN_URL settingwithself.settings(LOGIN_URL='/other/login/'):response=self.client.get('/sekrit/')self.assertRedirects(response,'/other/login/?next=/sekrit/')

This example will override the LOGIN_URL setting for the code
in the with block and reset its value to the previous state afterwards.

When given a class, these decorators modify the class directly and return
it; they don’t create and return a modified copy of it. So if you try to
tweak the above examples to assign the return value to a different name
than LoginTestCase or MiddlewareTestCase, you may be surprised to
find that the original test case classes are still equally affected by the
decorator. For a given class, modify_settings() is
always applied after override_settings().

Warning

The settings file contains some settings that are only consulted during
initialization of Django internals. If you change them with
override_settings, the setting is changed if you access it via the
django.conf.settings module, however, Django’s internals access it
differently. Effectively, using override_settings() or
modify_settings() with these settings is probably not
going to do what you expect it to do.

We do not recommend altering the DATABASES setting. Altering
the CACHES setting is possible, but a bit tricky if you are
using internals that make using of caching, like
django.contrib.sessions. For example, you will have to reinitialize
the session backend in a test that uses cached sessions and overrides
CACHES.

Finally, avoid aliasing your settings as module-level constants as
override_settings() won’t work on such values since they are
only evaluated the first time the module is imported.

You can also simulate the absence of a setting by deleting it after settings
have been overridden, like this:

@override_settings()deftest_something(self):delsettings.LOGIN_URL...

Changed in Django 1.7:

Previously, you could only simulate the deletion of a setting which was
explicitly overridden.

When overriding settings, make sure to handle the cases in which your app’s
code uses a cache or similar feature that retains state even if the setting is
changed. Django provides the django.test.signals.setting_changed
signal that lets you register callbacks to clean up and otherwise reset state
when settings are changed.

The failure messages given by most of these assertion methods can be customized
with the msg_prefix argument. This string will be prefixed to any failure
message generated by the assertion. This allows you to provide additional
details that may help you to identify the location and cause of an failure in
your test suite.

Asserts that execution of callable callable_obj raised the
expected_exception exception and that such exception has an
expected_message representation. Any other outcome is reported as a
failure. Similar to unittest’s assertRaisesRegex()
with the difference that expected_message isn’t a regular expression.

Asserts that a Response instance produced the given status_code and
that text appears in the content of the response. If count is
provided, text must occur exactly count times in the response.

Set html to True to handle text as HTML. The comparison with
the response content will be based on HTML semantics instead of
character-by-character equality. Whitespace is ignored in most cases,
attribute ordering is not significant. See
assertHTMLEqual() for more details.

Asserts that a Response instance produced the given status_code and
that text does not appears in the content of the response.

Set html to True to handle text as HTML. The comparison with
the response content will be based on HTML semantics instead of
character-by-character equality. Whitespace is ignored in most cases,
attribute ordering is not significant. See
assertHTMLEqual() for more details.

Asserts that the response returned a status_code redirect status,
redirected to expected_url (including any GET data), and that the
final page was received with target_status_code.

If your request used the follow argument, the expected_url and
target_status_code will be the url and status code for the final
point of the redirect chain.

The host argument sets a default host if expected_url doesn’t
include one (e.g. "/bar/"). If expected_url is an absolute URL that
includes a host (e.g. "http://testhost/bar/"), the host parameter
will be ignored. Note that the test client doesn’t support fetching external
URLs, but the parameter may be useful if you are testing with a custom HTTP
host (for example, initializing the test client with
Client(HTTP_HOST="testhost").

New in Django 1.7.

If fetch_redirect_response is False, the final page won’t be
loaded. Since the test client can’t fetch externals URLs, this is
particularly useful if expected_url isn’t part of your Django app.

New in Django 1.7.

Scheme is handled correctly when making comparisons between two URLs. If
there isn’t any scheme specified in the location where we are redirected to,
the original request’s scheme is used. If present, the scheme in
expected_url is the one used to make the comparisons to.

Asserts that the strings xml1 and xml2 are equal. The
comparison is based on XML semantics. Similarly to
assertHTMLEqual(), the comparison is
made on parsed content, hence only semantic differences are considered, not
syntax differences. When invalid XML is passed in any parameter, an
AssertionError is always raised, even if both string are identical.

Asserts that a queryset qs returns a particular list of values values.

The comparison of the contents of qs and values is performed using
the function transform; by default, this means that the repr() of
each value is compared. Any other callable can be used if repr() doesn’t
provide a unique or helpful comparison.

By default, the comparison is also ordering dependent. If qs doesn’t
provide an implicit ordering, you can set the ordered parameter to
False, which turns the comparison into a Python set comparison.

Output in case of error can be customized with the msg argument.

Changed in Django 1.6:

The method now checks for undefined order and raises ValueError
if undefined order is spotted. The ordering is seen as undefined if
the given qs isn’t ordered and the comparison is against more
than one ordered values.

Changed in Django 1.7:

The method now accepts a msg parameter to allow customization of
error message

Asserts that when func is called with *args and **kwargs that
num database queries are executed.

If a "using" key is present in kwargs it is used as the database
alias for which to check the number of queries. If you wish to call a
function with a using parameter you can do it by wrapping the call with
a lambda to add an extra parameter:

If any of your Django views send email using Django’s email
functionality, you probably don’t want to send email each time
you run a test using that view. For this reason, Django’s test runner
automatically redirects all Django-sent email to a dummy outbox. This lets you
test every aspect of sending email – from the number of messages sent to the
contents of each message – without actually sending the messages.

The test runner accomplishes this by transparently replacing the normal
email backend with a testing backend.
(Don’t worry – this has no effect on any other email senders outside of
Django, such as your machine’s mail server, if you’re running one.)

During test running, each outgoing email is saved in
django.core.mail.outbox. This is a simple list of all
EmailMessage instances that have been sent.
The outbox attribute is a special attribute that is created only when
the locmem email backend is used. It doesn’t normally exist as part of the
django.core.mail module and you can’t import it directly. The code
below shows how to access this attribute correctly.

Here’s an example test that examines django.core.mail.outbox for length
and contents:

fromdjango.coreimportmailfromdjango.testimportTestCaseclassEmailTest(TestCase):deftest_send_email(self):# Send message.mail.send_mail('Subject here','Here is the message.','from@example.com',['to@example.com'],fail_silently=False)# Test that one message has been sent.self.assertEqual(len(mail.outbox),1)# Verify that the subject of the first message is correct.self.assertEqual(mail.outbox[0].subject,'Subject here')

As noted previously, the test outbox is emptied
at the start of every test in a Django *TestCase. To empty the outbox
manually, assign the empty list to mail.outbox:

The unittest library provides the @skipIf and
@skipUnless decorators to allow you to skip tests
if you know ahead of time that those tests are going to fail under certain
conditions.

For example, if your test requires a particular optional library in order to
succeed, you could decorate the test case with @skipIf. Then, the test runner will report that the test wasn’t
executed and why, instead of failing the test or omitting the test altogether.

To supplement these test skipping behaviors, Django provides two
additional skip decorators. Instead of testing a generic boolean,
these decorators check the capabilities of the database, and skip the
test if the database doesn’t support a specific named feature.

The decorators use a string identifier to describe database features.
This string corresponds to attributes of the database connection
features class. See django.db.backends.BaseDatabaseFeatures
class for a full list of database features that can be used as a basis
for skipping tests.